Reload cached icons on density change.

import android.util.Log;

import android.util.SparseArray;

import android.view.Display;

import android.view.Gravity;

import android.view.IDockedStackListener.Stub;

import android.view.MotionEvent;

import android.view.Surface;

import android.view.WindowManagerGlobal;

import android.view.inputmethod.InputMethodManager;

import android.widget.LinearLayout;

import com.android.systemui.R;

import com.android.systemui.RecentsComponent;

import com.android.systemui.stackdivider.Divider;

import java.io.FileDescriptor;

import java.io.PrintWriter;

import java.util.ArrayList;

public class NavigationBarView extends LinearLayout {

    final static boolean DEBUG = false;

    private boolean mDockedStackExists;

    private final SparseArray<ButtonDispatcher> mButtonDisatchers = new SparseArray<>();

    private int mDensity;

    private class NavTransitionListener implements TransitionListener {

        private boolean mBackTransitioning;

        mShowMenu = false;

        mGestureHelper = new NavigationBarGestureHelper(context);

        mDensity = context.getResources().getConfiguration().densityDpi;

        getIcons(context);

        mBarTransitions = new NavigationBarTransitions(this);

            // we are switching to.

            setNavigationIconHints(mNavigationIconHints, true);

        }

        if (mDensity != newConfig.densityDpi) {

            mDensity = newConfig.densityDpi;

            getIcons(getContext());

        }

    }

    /**